package com.cctv.cndms.common;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

/**
 * @author heyingcheng
 * @category Class description
 * @email heyingcheng@ctvit.com.cn
 * @date 2018/9/12 12:39
 */
@Component
public class ApplicationContextHelper implements ApplicationContextAware {

    private static ApplicationContext applicationContext;

    public ApplicationContextHelper() {
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ApplicationContextHelper.applicationContext = applicationContext;
    }

    /**
     * 获取对象
     *
     * @param name
     * @return Object 一个以所给名字注册的bean的实例
     * @throws BeansException
     */
    public static Object getBean(String name) throws BeansException {
        return applicationContext.getBean(name);
    }

    /**
     * 获取类型为requiredType的对象 如果bean不能被类型转换，相应的异常将会被抛出（BeanNotOfRequiredTypeException）
     *
     * @param name
     *            bean注册名
     * @param requiredType
     *            返回对象类型
     * @return Object 返回requiredType类型对象
     * @throws BeansException
     */
    public static <T> T getBean(String name, Class<T> requiredType) throws BeansException {
        return applicationContext.getBean(name, requiredType);
    }

    @SuppressWarnings("unchecked")
    public static <T> T getBean(Class<T> requiredType) throws BeansException {
        String[] names = applicationContext.getBeanNamesForType(requiredType);
        if (names == null || names.length == 0) {
            throw new IllegalArgumentException("没有找到Bean, 类型：" + requiredType.getName());
        }
        return (T) applicationContext.getBean(names[0]);
    }

    public static Collection<Object> getBeans(String... names) throws BeansException {
        Collection<Object> beans = new ArrayList<Object>();
        for (String name : names) {
            beans.add(applicationContext.getBean(name));
        }
        return beans;
    }

    @SuppressWarnings("unchecked")
    public static <T> Map<String, T> getBeans(Class<T> requiredType) throws BeansException {
        Map<String, T> beans = new HashMap<String, T>();
        String[] names = applicationContext.getBeanNamesForType(requiredType);
        for (String name : names) {
            beans.put(name, (T) applicationContext.getBean(name));
        }
        return beans;
    }

    /**
     * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true
     *
     * @param name
     * @return boolean
     */
    public static boolean containsBean(String name) {
        return applicationContext.containsBean(name);
    }

    /**
     * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。
     * 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException）
     *
     * @param name
     * @return boolean
     * @throws NoSuchBeanDefinitionException
     */
    public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
        return applicationContext.isSingleton(name);
    }

    /**
     * @param name
     * @return Class 注册对象的类型
     * @throws NoSuchBeanDefinitionException
     */
    public static Class<?> getType(String name) throws NoSuchBeanDefinitionException {
        return applicationContext.getType(name);
    }

    /**
     * 如果给定的bean名字在bean定义中有别名，则返回这些别名
     *
     * @param name
     * @return
     * @throws NoSuchBeanDefinitionException
     */
    public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
        return applicationContext.getAliases(name);
    }
}
